William Brown poses for a photo at Xiamen University in Xiamen, Southeast China's Fujian province, June 14, 2018. [Photo/Xinhua]

William N. Brown, a United States professor at Xiamen University, Fujian province, was taken by surprise when he received a letter from President Xi Jinping ahead of the Chinese Lunar New Year.

The letter came after Brown, who began teaching within the university's MBA program in 1989, delivered his newly-published book Off the Wall: How We Fell for China and a letter to Xi days ago.

The book, consisting of 47 private letters that Brown wrote to his family and friends in the US over the past three decades, records and displays China's changes amid the historic campaign of the country's reform and opening-up process from a perspective of a US expat living and working in China.

"I feel truly happy and honored to receive a letter from President Xi, and also a big surprise," Brown told China.org.cn on Sunday.

In the letter to Brown on Friday, Xi lauded the professor's dedication of 30 years－during the prime of Brown's life－to the educational cause of China, and said he was touched by Brown's deep affection for Xiamen and the country.

Calling Brown an eyewitness to China's reform and opening-up, Xi appreciated him having represented Xiamen and Fujian province, and telling stories of China to the world.

Xi said he trusts Brown will witness a better and happier China with increasing prosperity and progress, and a nation that will create more benefits for the world and mankind.

As the Spring Festival, or Chinese Lunar New Year, falls on Tuesday, Xi extended holiday greetings to Brown and his family, wishing them Fu An (Fortune and Peace) and Chang Le (Long Happiness). Fuan and Changle are actually the names of two cities in Fujian province.

"Despite shouldering the huge responsibility and pressure of being the president of a country with the largest population in the world, he still managed to write back to an ordinary foreign teacher like me," Brown said. "I am more than willing to witness China's development in the following decades."

Brown said he and his wife met Xi in Fuzhou, capital of Fujian, in 2001, and during that meeting, he learned Xi had a deep understanding about the history and culture of the province.

Xi worked on various Party and government posts in the province from 1985 to 2002.

Southern Fujian province was the starting point of the ancient maritime Silk Road, and Xi knows very well about history. So the Belt and Road Initiative is something that came out of his mind after many years of careful consideration, Brown said.

Brown and his family moved to Fujian in the 1980s. Finding China very different from how he expected, the professor started writing about the region.

Brown became the first foreigner granted permanent residence by Fujian province in 1992, and in 1993 he received a Friendship Award by the Chinese government.